Adapter isDiscovering() behaviour

[srware]

I am seeing some strange behaviour with the isDiscovering() call in BluetoothAdapter.

I am frequently getting the following error when calling stopDiscovery() despite the isDiscovering() function returning "true":

org.freedesktop.dbus.exceptions.DBusExecutionException: No discovery started

I guess this exception should also be caught in the BluetoothAdapter.stopDiscovery() function. I am also wondering whether initialising the internalDiscover variable to false would help this although I guess that assumption could lead to other problems...

[hypfvieh]

The member internalDiscover is only used when startDiscovery() / stopDiscovery() is used. The method isDiscovering() will return true if internalDiscovery is true (when startDiscovery()was called and stopDiscovery()was not yet called), or if the DBus-Response says discovery is active.

The internal member does not need to be initialized with false, because that is the default for primitive boolean members in Java.

The exception might occur because internalDiscovery was not set correctly when startDiscovery() / stopDiscovery() was called due to exception catched in these methods. Therefore isDiscovering() still returns true/false and the start/stop method will be executed instead of being omitted.

Setting the member and calling start/stopDiscovery on DBus is not atomic, so in the current code, DBus is called first, then the member is changed. If DBus throws an exception, setting the member to true/false is never called, so the internalDiscovery flag has the wrong state.

I change the code to first set the member, then call DBus.

[srware]

Thanks for the explanation @hypfvieh

Is there a timeline for a new release incorporating some of the recent fixes?

[hypfvieh]

no there is no timeline